Magnet



Oct. 12, 1948,

R. l.. MAN EG'OLD MAGNET Filed Dec. l1l 1944 INVENTOR.

Patented Oct. 12, 17948 UN ITE-D STATE S PAT ENT `O FF ICE MAGNET `Robert Mancgold, Milwaukee, Wis., assig-norto Dings Magnetic Separator Co., 'Milwaukea IWS., a corporation oi" Wisconsin Application .December 11, 194.4, .Serial No. 567,602

Claims.

This invention relates in general to apparatus for removing undesirable metallic objects from cavities, and relates more .specically to an improved magnet or eiiecting withdrawal of broken drill bits or the like from deep holes in which the defective bits have become lodged during lformation of the holes.

The primary object of my invention is to provide an improved simplied and highly efficient magnet for effecting ready removal of broken drill rods, bits or the like from holes within which the broken parts have become lodged When drilling holes in rock, concrete, ore, and the like, With the aid of so-called rock drills, it frequently happens that the drill rods or bits break away from the drill rod and become lodged in the bottoms of the holes after considerable drilling depth has been attained. In such cases, it is necessary in order to continue the drilling operation in the same holes, to remove .the.ob structing broken oli" bit points, and if this cannot be done, new holes must be drilled at considerable expense and effort. While various methods of removing such broken drill bit fragments from the holes within which .they are confined, have heretofore been proposed, these prior methods and apparatus were so ineffective and complicated, that the trade would usually resort to the drilling of new holes rather than attempting to salvage the plugged ones.

Recent developments in the production of Ipermanently magnetic alloys, such as a .mixture of aluminum, nickel, cobalt and iron, have made ,it possible to produce verycompact and `powerful U-shaped magnets, and I Vhave discovered that such a permanentmagnet canbeutilized to great advantage for the removal of magnetic objects such as drill bits fragmentsirom deep `cavities or the like. Such permanently magnetic compositions are however extremely hard and cannot be machined by ordinary methods, and since it is necessary'to insert 'and to manipulate the bit removing magnets within the holes, ,some means must be provided forsuch purposes. The'most convenient manner Yof thus `handling the U- shaped magnet, is tomake'the .Samereadily-detachably applicable to the threaded end 'of Aan ordinary drill rod, and lI have found that this may be done by rproviding uthe permanent U- shaped magneticV body withathreaded endsocket the same as that which is formed in theordinary standard drill-bit. ASuch-a socket lmay'eitherbe cast directly withintlie magnet when the-latter is being initially -iormed, for-it may 'be-produced in a Vseparatesocket @element secured;tothe4 cast 2 magnet body by ,a Vsingle "bolt Vor the like, thus avoiding necessity of machining the hard inagnetic material.

It is .therefore a more specific object of the present invention to provide a new and useful permanently magnetic and powerful drill bitremover;havingmagneticpoles of opposite polarity at one end, .and being provided at its opposite end .with asocket formed for detachable Aattachment to an lordinary drill rod, either by lscrew areading orotherwise.

VAnother specic object of this invention .is1to provide an extremely simple, compact, and effcient drill Vbit removing magnet adapted to be readily inserted and manipulated within ajhole containing a brokenbit vOrother obstruction, with the'aid of a standard drill rodl Still another specificobject of myinventionlis to provide an improved drill bit removing implement comprising a hard permanently magnetic prismatic .body `formed by casting and ,havingla U-shaped Ipermanent magnetat .oneend and la screw threaded socket ,at vits opposite endand adapted to )be conveniently inserted .withiuand 4removed from relatively deepholes.drilledjnrock, concrete or the'like. 4

These and other speciiicobjectsof the invention will be apparent from theffoillowng detailed description. v

A clearconeeption of the featuresconstituting my present improvement, V,and of .the mode .of constructing and of utilizing severaltypeslotmy improved drill bit removing,magnetlmay'behad by referring tothe drawing .accompanyingand forming a part of vthis specicationwherein .like reference Vcharacters designate the 4same or similar parte in the variousviews.

Fig. l is a central longitudinal section through a .one-piece drillbit removirm 4magnet. embodying the invention, showing the same'in theactfpf removing a broken drill 'bit and rodend 'from.a hole formed bythe bit;

Fig. 2.is a side elevation of -the one-piece -`bit removing permanent magnetof Fig. '1;

Vliig.z3 is an end viewofthe same magnet' looking'toward the magnetic, poles;

l Fig. 4 is a central longitudinal `section through a modified two-section ldrillbit removing magnet also embodying the invention, likewise showing the same .in the act Yof removing a broken A,drill bit uandrod end'from a hole previously .formefdby thebit; 'and Fig. 51is-a side velevationpf the compoundmagneticbit remover, showrtingFigg. f

V-Wl1ilethe"inventionhas been shown and descope or utility of the improvement for other.

purposes.

Referring especially to Figs. 1 to 3 inclusive,

the improved drill bit remover shown therein comprises in general a one-piece prismatic body 'I formed of hard material adapted to be intensely permanently magnetized, having parallel laterally spaced poles 8, 9 of Vopposite polarity at one end, and also having an internally screw threaded socket I provided in its opposite end. Referring more particularly to Figs. and 5, the modified improved drill bit remover shown therein, comprises generally a prismatic body II formed of one end section I2 of hard material adapted to be intensely permanently magnetized and having laterally spaced poles 8, 9 of opposite polarity formed integral therewith, and anotherV end section I3 of ordinary machineable material providedwith a screw threaded socket I0, the sections I2, I3 coacting with each other along plane interveningsurfaces I4 and being firmly united by means of a boltv|5 and nut I6 coacting therewith.

The bodies 1, |I may be cylindrical as shown, or of any-other suitable prismatic shape, and thebodyl 7 and the. end section I2 of the body I I are preferably formedrby'casting, of very hard and relatively non-machineable metal composition such as Alnico comprising ingeneral a combination of aluminum, nickel, cobalt and iron. Such material while being most difficult to machine or finish with the aid of cutting tools, is adapted to be intensely permanently magnetized, so as to provide VU-.shapedmagnets having powerful magnetizedlpoles 8,. 9 of opposed polarity. When the one-piece b'ody 'I of Figs. Yl; Zand 3 is.v cast, the-relatively rough internal screw threads of the socket Il! thereof, are pref- 'erablyformed during the initial casting operation; but in the modified two-section body I| of Figs. 4 and 5, the section I2 may. be cast with a central hole for'receiving the bolt I5, While the other section I3 may be formed of softer metal in which the screw threads of the socket I0 may be readily cut and the bolt receiving hole may beeasily drilled. Both types of prismatic magnetized bodies 1, II, however function and areusable in like fmanner, so that a description of the normal use of one will suffice for the other.

During normal use of the improved drill bit removing magnet, and assuming the same to have ybeen properly constructed as above described, either device may then 'be utilized to quickly and effectively remove a drill bit fragment Il' and broken rod end I8 embedded therein, from a deep hole I9'previously formed by the .drill bit in a bed of rock or concrete. 29, in the followingrmanner. Loose debris should preferably be initially ushed from within the hole I9 in a well known manner, so as to leave the broken surfaces 'of the fragment II and rod end I8 exposed, whereupon the body 'I maybe applied to the threaded end of a drill rod 2| in an obvious manner. The drill rod 2| may then be utilized to insert the magnet body I within the hole I9 so as to bring the prongs or poles 8,' 9 of the magnet in contact with the broken surfaces of the fragment, I1 and rod end I8, after which the drill rod 2| vmay also Vbe utilized to withdraw the broken bit and rod fragment from within the hole I9. Because of the great power i exerted bythe poles 8, 9,thisshing operation may be most effectively performed, and the drill bit and rod fragments can be quickly and conveniently removed so as to permit further drilling operations to be carried on.

From the foregoing detailed description it will be apparent that my present invention provides an extremely simple, compact and highly efficient appliance for effecting quick and convenient removal of drill bit fragments or the like from drilled holes of any depth. The improved drill bit removing magnet may be quickly associated with a standard drill rod 2|, and conveniently manipulated to perform its function, and the improved device can also be manufactured and sold at moderatecost .andl may be readily manufactured in quantities to fit various sizes of drill rods 2|. While .the one-piece magnet assemblage of Figs. 1 to 3 inclusive is simpler than the two-section structure of Figs. 4 and 5, accurate manufacture of the device may be facilitated by forming the body of two sections, and in both cases the U-shaped magnet provides powerful instrumentality for effecting ree moval of `the metal fragments'from .within the other suitable type of fastener may obviously be substitutedV for these clampingV elements. I t is also noteworthyy that in actual practice, either thebit Il or the threaded lowerend of the drill rod 2|, or both may break away from the remainder of the drillrod propenaand. the improved magnet may be utilized toY remove .any metallic parts which may becomelodged in either shallow or deep holes.

. It should be understood that it is not desired tolimit this invention tothe exactdetailsof construction, or to the precise mode of use, herein shown and described, for variousrmodiflcations withinthe scope of .theappended claims may occurto persons skilled inv the/art.A f Y `I claim: .Y

1. A drillrbit removing magnet, comprising, a

U-:shaped powerful magnet having anat end. surpowerful U-.shaped magnet of substantiallycylin- Y drical contour having .an open slot invone end forming magnetic poles and'being provided at its opposite end 4with an opening betweenthepoles, a socketedV .member having `internal lattaching screw threads within the socket thereofand also having an opening through thebottom of -the 'socket alineable with.said'magnetppening, and

magnetand mem-KV a fastener rigidly uniting said ber at said alined openings.. .a

., 3. A drill bit removing Vdevice,comprising, an

intensely., .permanently mag'netizedY U-'slflaped l magnet having an openingtherethrough between the poles thereof,'an internally Nthreaded;socket member jhaving' an. opening alineablei wil-,hfsaidV magnet opening, and afasteneriirmly butde-V Y tachablyV uniting said magnegancl member ,fsgd openings.

4. .A .drill bit removing device, comprising; an k. Y intensely permanently` magnetizedV U-shaped f magnet having-an @perline therethrough between theroles'ihereffa Socketed-.zmemberhavmsdn# e ternal attaching screws within the socketthereof and also having an opening through the bottom of the socket alineable with said magnet opening, and a fastener rmly but detachably uniting said magnet and member at said openings.

5. A drill bit removing device, comprising, an intensely permanently magnetized U-shaped magnet having an open slot in one end forming magnetic poles and being provided at its opposite end with a central opening between the poles, a socketed member of approximately the same transverse cross-section having internal attaching screw threads within the socket thereof and also having a central opening through the bottom of the socket aiineable with said magnet opening, 15

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 604,327 Hurst May 17, 1898 974,760 Eastwood Nov. 1, 1910 1,094,106 White Apr. 21, 1914 1,439,687 Brandon Dec. 26, 1922 FOREIGN PATENTS Number Country Date 761,687 France Jan. 13, 1934 

